How to pronounce 完蛋 in Cantonese (2 out of 3):

你很快完蛋
You're almost done.

Cantonese Sentence Breakdown

nei5
you (informal, as opposed to courteous 您nín [您])
can be used to refer to an unspecified person
han2
very
faai3
fast
完蛋 yun4 daan6
doomed